I just had a look through the crew bios for STS-122 and its interesting to note that the youngest astronaut will be 43 this year (Stanley Love) while the oldest will be 57 (Hans Schlegal). Also 4 are rookies while all the others have flown only once.

Now aside from the fact that this obviously shows there is not much chance to get a ride at NASA and that you could be nearing retirement by the time you get a second, I was wondering whether NASA was picking older astronauts for the few remaining shuttle flights as they know they wont be around when Orion eventually flies. Or possibly it just reflects the fact that the average age of a NASA astronaut is in his mid 40s.

The same appears to be true for ESA whose 2 astonauts are in their 50s.

While astronauts no doubt are in peek physical condition, it no wonder NASA doesnt appeal to kids these days when the people it is sending to space are old enough to be their grandfathers.

Good luck to the astronauts who are installing Columbus at the ISS.

_________________A journey of a thousand miles begins with a single step.

In general "older" astronauts are preferred because of the radiation dose they collect in space. Many multiple-fliers like e.g. Story Musgrave were denied additional flights because flight surgeons and NASA regulations forbid it.

And as radiation damages the genes as well NASA clearly prefers (not only because of that) astronauts who already have children.

About Orion and future astronauts. I think for the first flights, NASA will only need "professional" astronauts, that is no mission specialist, only commander and pilot. (The mission specialists can fly with the Soyuz *g* to the ISS in the phase the US has no manned access to space). And for that task you don't need that many, so a remaining astronaut corps of perhaps 5 commanders and 5 pilots would be enough.

_________________"The hardest hurdle to space isn't the technicalities and money. But rather, the courage and the will to do it." - Burt Rutan.

If NASA only require a complement of 10 astronauts for the first Orion flights I think that becoming a NASA astronaut is likely to become harder, I can see a lot of their current astronauts defecting to companies like Bigelow if they want to get into space.

This is another example of NASA not opening space up but keeping it the preserve of a few select people. You can see why people are not engaged by NASA as they see they have no stake in it.

With regard to the radiation dose, I think that I'm right in saying that the the amount is lower in a bigelow inflatable because they use a water layer as a screen between membranes.

_________________A journey of a thousand miles begins with a single step.

Many astronauts are already leaving NASA. You just have to look back the last 1,2 years. Nearly every month NASA is reporting 1, 2 times that another astronaut left them.

For the ISS, NASA perhaps needs 5-6 astronauts a year from 2010 on for 5 years. So 20 mission specialists are enough. For the first Orion missions take the 10 "command" astronauts, so you have an astronaut corps of perhaps 30.

For later Orion missions (say Moon missions) it's still enough time to recruit new astronauts (perhaps from 2015 on) when and in case it will become clear that the Moon missions will actually become reality.

_________________"The hardest hurdle to space isn't the technicalities and money. But rather, the courage and the will to do it." - Burt Rutan.

What is the curent number of astronauts working for NASA who are hoping/scheduled for a flight?

I know a lot of them do other things within the orgaisation and at some point they must retire from active status to help with some of the important backroom stuff like mission planning and spacecraft design.

_________________A journey of a thousand miles begins with a single step.

Thats going to be a lot of dissappointed people. Looking down the list some of these guys are in their 60s and older, aside from the fact that there dosent appear to be a retirement age at what point are they considered ex-astronauts?

I wonder whether NASA will suspend astronaut intakes to try to reduce numbers or possibly push more into management duties. I dont think that making people push paper is a good recruiting policy and if it was me I would leave to find a job where I had some chance of getting to space.

_________________A journey of a thousand miles begins with a single step.